Purpose: The goal of this work was to analyze the stress distribution in 2 wedge-shaped implant designs, straight and angled, by means of a 3-dimensional finite element method (FEM) stress analysis. Materials and Methods: A model was generated from computerized tomography of a human edentulous mandible with the implants placed in the left first molar region. The model included boundary conditions representing the muscles of mastication and the temporomandibular joint. An axial load of 100 N and a horizontal load of 20 N were separately applied at the tops of the implant abutments, and system equilibrium equations were used to find each muscle intensity force based on its position and direction. The mandibular boundary conditions were modeled considering the anatomy of the supporting muscle system. Cortical and medullary bones were assumed to be homogeneous, isotropic, and linearly elastic. Results: The stress analysis provided results in terms of normal maximum tensile (s1) and compressive (s3) stress fields. The stress distribution was quite similar for both designs, indicating a good performance of the angled design. Conclusions: Stresses in the angled implant were in general lower than in the straight implant, and the differences between the 2 designs studied were more relevant for the vertical load. No indication was found that angled implants of the type described generate stress-induced problems compared to straight implants. Int J Oral Maxillofac Implants 2008;23: 215–225

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